Lookup Country and Area code

Enter a telephone number. Format: 00, Country code and Area code without trunk prefix.
E.G.: 003120, 00331, 004420, or 004930;

• A leading '+' will be replaced by '00'.
• Anything between brackets, '(...)' will be ignored;
  Don't put the area code in brackets!
  You can put the trunk prefix in brackets though.
• All non-digits are ignored as well.

So, for instance, '+ 31 (0) 20' becomes '003120'.

This form is based on the Asterisk name and location lookup AGI, which displays names and locations on SIP phones.
Names are shortened to 20 characters. If you know a better way of doing this, please let me know.
If you find any errors, please let me know.